Chapter 43: The Nervous System

Question 1

Central Nervous System

Answer 1

information processing system (CNS)

brain and spinal cord

Question 2

Peripheral Nervous system

Answer 2

PNS

includes the afferent division, and efferent division (which splits into somatic and autonomic nervous systems)

Question 3

Afferent division

Answer 3

Part of PNS

transmits sensory info; can determine significance of info after processing

Example: seeing colors, sensing motion in hair

Question 4

Efferent division

Answer 4

Part of PNS

transmits motor info

includes the somatic and autonomic (parasympathetic and sympathetic) systems

Question 5

Somatic nervous system

Answer 5

made up of motor and sensory neurons

includes voluntary movement and control

Question 6

Autonomic nervous system

Answer 6

includes involuntary movement (adrenaline, dilated pupils, and heart racing)

parasympathetic and sympathetic systems

Question 7

Parasympathetic

Answer 7

rest and digest response

slow heart rate, constrict pupils, stimulate salivation, stomach and intestine activity, contract bladder, inhibit release of glucose from liver

Question 8

Sympathetic

Answer 8

fight or flight response

heart racing, pupils dilated, relax bladder, inhibit stomach and intestine activity, secrete epinephrine and norepinephrine from adrenal glands

Question 9

Neurons

Answer 9

fundamental parts of the brain and nervous system, recieve sensory inputs from external world

Question 10

dendrites

Answer 10

convert chemical signals to electrical signals
 Chemical, sound based, light etc

Question 11

cell body

Answer 11

where dendrites are attached to; integrates incoming electrical signals(what do to with them); If significant enough, sends signal down axon

Question 12

Axon

Answer 12

conducts electrical signals
 Can be quite a long length!

Question 13

three main types of neurons in nervous system

Answer 13

sensory neurons, interneurons, and motor neurons

Question 14

Sensory neurons

Answer 14

These are specialized neurons that are responsible for detecting sensory stimuli from the environment and transmitting this information to the central nervous system.

Sensory neurons have specialized receptor cells that respond to different types of stimuli such as light, sound, touch, temperature, and chemicals.

They are located in sensory organs such as the eyes, ears, nose, tongue, skin, and internal organs.

Question 15

Interneurons

Answer 15

Interneurons are located in the spinal cord and brain and act as intermediaries between sensory neurons and motor neurons. They integrate and process the information received from sensory neurons and transmit signals to motor neurons or other interneurons. Interneurons are responsible for many of the complex functions of the nervous system such as perception, memory, learning, and decision-making.

Question 16

Motor Neurons

Answer 16

These neurons are responsible for transmitting signals from the brain and spinal cord to the muscles and glands, allowing for movement and secretion. Motor neurons are divided into two types: somatic motor neurons, which control voluntary movement of skeletal muscles, and autonomic motor neurons, which control involuntary movement of smooth muscles, cardiac muscles, and glands.

Question 17

How does information flow in neurons?

Answer 17

dendrites (convert chemical signals to electrical signals) -> cell body (integrates incoming electrical signals ) -> axon (conducts electrical signals)

Question 18

Myelin Sheath

Answer 18

insulation of axon

Made up of Schwann Cells and Oligodendrocytes

Question 19

Immune system (neurons)

Answer 19

 Microglia are primary caretakers
 Astrocytes help

Question 20

Blood brain barrier

Answer 20

controls what gets in and out of nervous system

Astrocytes can do this

Question 21

Resting membrane/membrane potential

Answer 21

electrical potential difference across a biological membrane
o Created by separation of charged ions across the membrane; more positive ions on one side and more negative ions on the other side
o Difference in charge creates voltage gradient, measured in millivolts (mV)

Question 22

Contributors to membrane potential

Answer 22

Na/K pump

intracellular proteins

K leak channels

Question 23

Na/K pump

Answer 23

pushing out Na+, kicking in K+
* Does not affect -70mv (resting potential) until change happens with some other contributors

Question 24

Intracellular proteins

Question 25

K leak channels

Answer 25

strongest contributor to membrane potential! Puts in motion of change with other contributors; allows K+ to diffuse in and out

Question 26

3 main changes to membrane potential

Answer 26

polarization, depolarization, and hyperpolarization

repolarization involved in some ways

Question 27

Polarization

Answer 27

refers to the state of the membrane potential when there is a separation of charge across the membrane, resulting in voltage difference between inside and outside the cell

 Can happen when inside of the cell is negatively charged relative to the outside

Question 28

Depolarization

Answer 28

often referred to as excitatory stimulus
o Membrane potential becomes less polarized; voltage difference across membrane is smaller
o Occurs when positively charged ions enter the cell or negatively charged ions exit the cell
o KEY STEP in generation of action potentials

Question 29

Hyperpolarization

Answer 29

often referred to as inhibition
o Membrane potential becomes more polarized, voltage difference across membrane becomes larger
o Negatively charged ions enter the cell or positively charged ions exit the cell
o Harder to create an action potential, is increasing difference the action potential must overcome

Question 30

Repolarization

Answer 30

involves multiple excitatory events that cause greater depolarization (can lead to action potentials)

Question 31

Graded potentials

Answer 31

 Driven by opening and closing of ligand-gated ion channels
 When a ligan (acetylcholine) binds a receptor, a sodium channels is opened
* Membrane will then experience small, brief depolarization

Question 32

Give a summary of the ability of graded potentials to combine

Answer 32

1) Depolarization: often referred to as excitatory stimulus
2) Multiple excitatory events cause greater depolarization
3) Hyperpolarization: often referred to as inhibition
* 4) summarization/summation of 1, 2, and 3
* ** If enough summarization/summation occurs, you can produce action potentials!